Vacuum-valve detector



R. AWEAG/Nr VACUUM VALVE DETECTOR..- APPLICAUON FILED MAR. 10.1191?.

Patened May 3L i923;

ROY ALEXAN'DER WEA-.GAN T, OF

nnLAwAnE.

following is a specification.

This invention' relates to vacuum valve devices used to detect or amplify electrical oscillations of audioor radio" frequenc, rf

the general type described in Fleming Patent 803,684, and Vparticularly to those l having-a structure' similar to the valve disclosed in my prior application', Serial N20.

In using devices like that shown in my said application comprisingan exteriorcontrol element, which projects an electro-static field into the -path I of the electron stream,

element, when its potential lis raised bya received impulse,

diilculty has been experienced from strong ances which rendered the tube or valve temporarily inoperative, varying in time from affraction' of a second to ten or fifteen minutes. This diiiculty is of a serious nature in the commercial use of the device as interruption of the functions of the tube occur every time Such strong electrical disturbances take place. The object'of this inven-l tion is to overcome or obviate the defects named. ll-accomplish this object by the improved arrangement described herein. This .arrangement includes a vacuum tube, two electrodes,

one of which is preferably heated, and a guard device located lwthin the vacuum. The electrodes are preferably so disposed that they are comparatively close to. eachother at one point only, and the mean distance separating them is comparatively great compared to the distance at that point. This is desirable in that it provides a short path for a portion of the electron flow and tends tov make the electron flow continuous notwithstanding static. The guard device referred to is preferably in the form'of a ring and is preferably disposed at'g-"oradjacent the point -where the electrodes l fr-cach each other and is electricallyfconnected to the hot electrode. Tt

@pentes-td discharge any' charge that occurs Specification of Letters Patent. v

, guard devlce,

electrical disturbl for known.

freres.

g RO'SEILE, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS, .TO RADIO CORPORATION OFl AMERICA, A CORPORATION VACUUM-VALVE DETECTOR.

I rammen May si, rear.

' Application n'led maren 10, 1917. serial No. 153,934.

or accumulates on the interior wall of the tube in the 4vicinity of its location. l

he accompanying vdrawing illustrates the preferred embodiment of my invention.

Figure l shows the complete vacuum tube "with its two inclosed electrodes, the guard device, and the exterior control electrode connected-in the circuits of a wireless tele. graph receiver. Fig. 2 shows the tube in perspective omitting the exterior control element to make clear .the relative position of 4the parts.

The tube, t, is of glass, evacuated td any desired degree. The hot electrode is a filament, f, and the cold electrode, c, is a wire of metal preferably including helical turns, 5. The wire forming electrode c-is preferably of small diameter and is preferably placed to embrace the central axis of the tube, its tip pointing at the cathode. The

and is supported at 7, preferably in contact with the inner wall ofthe tube as shown, and is electrically connected to filament, f, by a metal wire conductor, 8. The guard device is preferably located so as to surround the space between the electrodes, as

" shown in the drawing, but'good results may also be had by placing it around the hot filament. All of the above mentioned parts are sealed in the tube. Outside the tube, t, is an electrostatic control element, e, preferably a cylinder 4of, brass or copper fixed firmly onto the exterior surface of tube, t. In extent, lthis element, e, preferably incloses all the active area of electron flow including elements c and f, and mayveven overlap this area. Thus the the control elemente. vice d extends over only a relatively small portion of the part-of the tube in which the electron .How occurs.

The circuit shown in Fig. l is'well known use with vacuumdetectors. The antenna,.a, adjustableinductances 9 and 10 aslsociated as transformer coils and the adjustable condensers, l1 and 12, are well i The battery is in circuit with head telephone, 14. The circuit, l5, is con- 'attery and add' guard device, d, always lies within the Zone covered by Moreover, the ded, is in the form of a ring,

ido

justable resistance are shown at 16, 17. The `electrical connections '18 and 19 electrically unite cold element c, and control element e, to opposite terminals of coil 10, and the condenser 12. v p

In operation by proper adjustment of battery, 00, the heating means 16, 17 and the condensers, 12, the tube maybe used as a detector, amplifier or generator of oscillations. When static or other effects tend to cause the tube` to become plugged, that is, to suspend its functions, the guard device prevents the accumulation of a charge on the interior of the walls of the tube, and

thus maintains the device in operative cony dition.

While I have described lonly one modification of my improved device, Iam aware that other modifications may be made by those skilled in the art andr I desire protection for all such modifications as come within the scope of my claims.

What I claim is: .l

1. A vacuum tube device of the kind described, comprising an evacuated vessel, a hot electrode and a cold electrode sealed within said vessel, means a charge on the interior wall of said vessel, said means located intermediate said electrodes, and means whereby said first mentioned means is maintained at thesame potential as s aid hot electrode.

2. A vacuum tube device of the kind described, comprising an evacuated vessel, a

hot electrode and a cold electrode sealedv within said vessel, a control element located outside said vessel in close proximity to its walls, a device for discharging Aa charge on the interior wall of said vessel, and means whereby said device is maintained at the same potential as a portion of said hot electrode.

3. A vacuum tube device of the kind described comprising an evacuated vessel, a hot electrode and a cold electrode sealed within said vessel, a control element located outside of the vessel, a metallic wire ring located within said vessel in close proximity to its walls, and means whereby said ring is maintained at the same potential as said hot electrode.

L1. In a device of the character described, a vacuum chamber; a hot electrode, and a cold electrode, separated, chamber, and so arranged that the mean distance between all parts of said electrodes is relatively great as compared with the distance between a point on one and a point on the other, in combination with a device lo cated intermediate said elements for discharging a positive charge on the interior wall of said chamber, and means for maintaining said device at the same potential as said hot electrode.

5. In a device of the character described,

taining said device for discharging sealed within said4 point on the other in combination with a device located intermediate said two elements for discharging a charge on the interior wall of said chamber, means for mainat the same potential as said hot electrode, located outside said chamber, in close prox- Vimity thereto.

6. In a device of the character described, a vacuum chamber, a hot electrode, and a cold electrode, separated and sealed within said chamber so that the mean distance between all parts of said electrodes is relatively great as compared with two points, one on each electrode, in combination with a ring shaped device located intermediate said electrodes for discharging a charge on the interior wall of said chamber and means for maintaining said` ring at the same potential as said hot electrode.

7 The combination with a thermionic device of an external electrostatic 'control elementl there-for, and lmeans for discharging a charge produced-on the interior of said device `when said element is charged.

8. The combination of a thermionic device having any anode and a hot cathode therein, of an electrostatic control element supported by the thermionic device for rapidly varying the value of Athe thermionic current between said electrodes, means for indicating changes' in value of said current and means for discharging a charge produced o-n the inner surface of said device when said element is charged.'

9. The combination with a thermionic device having an anode and a hot cathode therein, of an electrostatic control element associated with the thermionic device for rapidly varying the value of the thermionic current between said electrodes, means for indicating changes in value of said cur rent and means for discharging a charge produced on the inner surface of said device when said element is charged, said means being electrically connectedto a portion of said cathode.

10. The combination with a thermionic device havingan anode and a hot cathode therein, of an external electrostatic control element therefor, and means for discharging a charge produced on the interior of said` device when said element is charged, said discharging means being connected to said cathode.

11. The combination with a thermionic device having a spaced anode and cathode of an external therefor extending. the entire distance beand a control electrode,

electrostatic control element`VV` neaaroe C@ tween said anode and cathode, and means for discharging a charge -produced on the interior of said device when said element is charged.

l2. As an article of manufacture, a thermionic device having an anode formed with a wire-like portion pointing toward the cathode having its end separated therefrom by a distance relatively small as compared with the average distance between said cathode and anode.

13. As an article of manufacture, a thermionic device having an anode formed with a substantially straight tip pointed toward a hot cathode having its end separated therefrom by a distance relatively small as compared with the average distance between` said cathode and anode.

14. As an article of manufacture, a thermionic device having an anode formed with a substantially straight tip pointed toward a hot cathode and a guard ring whose plane is close to the end of said anode and which is connected to said cathode.

l5. As an article of manufacture, a therniionic device having an anode formed with a substantially straightJ tip extending toward tie hot cathode, a guard ring whose plane is close to the end of said anode and which is connected tc said cathode, and an external electrostatic control element.

16. A vacuum tube device of the kind described comprising an evacuated vessel, a heated filament and an electrode sealed within said vessel, a source of continuous current having its negative pole connected to said filament and its positive pole connected to said electrode, an electrostatic control element for the thermionic current, means for discharging a charge produced-on the inte.-

rior of said vessel when said control element is charged and means whereby said first means is maintained at the same potential as a part of said cathode.

17. A combination of an evacuated vessel having an anode and a hot cathode therein, of an electrostatic control element supported by said vessel in close relationship with the electron stream between said electrodes whereby the value of the thermionic current therebetween may be rapidly varied, means for discharging aqcharge produced on the interior wall of said vessel when said control element is charged and means whereby said first means is maintained at the same potential as a part of said cathode. 

